In a system or network in operation, for example, communication packets (hereinafter also simply referred to as packets) flowing in the network are sometimes acquired and analyzed to grasp an operation state. The acquisition of the communication packets is performed by providing capture points in places where the analysis target communication packets pass. In general, the capture points are provided in a plurality of places in order to make it possible to comprehensively acquire the communication packets needed for the analysis.
The communication packets sometimes pass a plurality of capture points depending on a network configuration and the like. In this case, the analysis of the communication packets is performed assuming that the same packet is generated a plurality of times. Therefore, when such communication packets are generated, in the analysis of the communication packets, the number of communication packets may be sometimes unable to be correctly calculated. Further, for example, it is sometimes determined that retransmission is performed because a packet loss occurs. Therefore, in general, the analysis of the communication packets is executed after a redundancy check of received communication packets is performed (see, for example, WO 2010/086907, Japanese Patent Application Laid-Open No. 2009-130528, Japanese Patent Application Laid-Open No. 2008-219127, and Japanese Patent Application Laid-Open No. 2010-72955).